The present invention relates to an optical circuit board that facilitates a mounting process and provides advantageous aspects of electric interconnection and optical interconnection.
With the expansion of services and applications for handling a large capacity of data such as images in the electronic equipment such as personal computers, cellular phones and television sets, the developments of high-speed and large-capacity data communication technologies are being promoted. In this technical environment, optical interconnection attracts the attention for enabling high-density, high-speed and large-capacity data communication within the electronic equipment or among a set of electronic equipment. In this context, “high-density” means a high transmission capacitance per unit volume. For example, the optical communication is recognized to be a high-density communication because the diameter of the single transmission line for transmitting the signal optically is 1 mm or smaller in contrast to the fact that the diameter of the single transmission line for transmitting the signal electrically is several millimeters.
In the prior art for the electric interconnection within the electronic equipment or among a set of electronic equipment, the high-speed signals may be converted temporarily into the low-speed signals, and then the converted signals are distributed into multiple (plural number of) electric interconnections placed at the flexible FPC (Flexible circuit board, hereinafter referred to as FPC). Coaxial cables are used as electric interconnections for transmitting signals faster than the electric interconnections on the flexible circuit board, and thus, by using coaxial cables, the number of multiple electric interconnections to be distributed can be reduced to be less than the number of electric interconnections on the flexible circuit board.
In order to make the signal much faster, it is required to implement the waveform correction circuit for correcting the waveform turbulence near the terminal end of the electric interconnection caused by the signal delay, etc. in the electric interconnection.
The optical interconnection for transmitting signals faster than the electric interconnection is mainly used for the long-distance information transmission, for example, intercontinental and inter-city networks which use optical interconnections for single mode transmission with less delay in the optical pulse. As for the short-distance LAN (Local Area Network), from the view point of easiness in connectivity of optical interconnections, multi mode transmission is mainly used in order to enable to make the diameter of the core of the optical interconnection larger.